Support concatenation of asm script files

[maurermi]

Description

Supports execution of multiple scripts chained together

Overview

Thanks for creating this project, I have found it quite nice to use recently in an educational context.

Made a very small addition that I have found useful, which just reads in multiple files concatenated together. This was nice for the question of "does script X unlock script Y". Figured I'd PR it in case it's useful for others!

Testing

Try writing up two scripts and execute them together
Ex.

# makes-eight.bs
OP_1
OP_DUP
OP_ADD
OP_DUP
OP_ADD
OP_DUP
OP_ADD

# checks-equal-to-eight.bs
OP_8
OP_EQUAL

Executing:

$ btcexec ./makes-eight.bs ./checks-equal-to-eight.bs
Script in hex: 517693769376935887
Script size: 9 bytes
--------------------------------------------------
Execution ended. Success: true
Final stack: <01>
Stats:
ExecStats {
    max_nb_stack_items: 2,
    opcode_count: 0,
    start_validation_weight: 51,
    validation_weight: 51,
}
Time elapsed: 0ms

Executing with --debug

)$ btcexec ./makes-eight.bs ./checks-equal-to-eight.bs --debug
Script in hex: 517693769376935887
Script size: 9 bytes
--------------------------------------------------
Remaining script: OP_PUSHNUM_1 OP_DUP OP_ADD OP_DUP OP_ADD OP_DUP OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: 
AltStack: 
--------------------------------------------------
Remaining script: OP_DUP OP_ADD OP_DUP OP_ADD OP_DUP OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: <01>
AltStack: 
--------------------------------------------------
Remaining script: OP_ADD OP_DUP OP_ADD OP_DUP OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: <01> <01>
AltStack: 
--------------------------------------------------
Remaining script: OP_DUP OP_ADD OP_DUP OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: <02>
AltStack: 
--------------------------------------------------
Remaining script: OP_ADD OP_DUP OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: <02> <02>
AltStack: 
--------------------------------------------------
Remaining script: OP_DUP OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: <04>
AltStack: 
--------------------------------------------------
Remaining script: OP_ADD OP_PUSHNUM_8 OP_EQUAL
Stack: <04> <04>
AltStack: 
--------------------------------------------------
Remaining script: OP_PUSHNUM_8 OP_EQUAL
Stack: <08>
AltStack: 
--------------------------------------------------
Remaining script: OP_EQUAL
Stack: <08> <08>
AltStack: 
--------------------------------------------------
Remaining script: 
Stack: <01>
AltStack: 
--------------------------------------------------
Execution ended. Success: true
Final stack: <01>
Stats:
ExecStats {
    max_nb_stack_items: 2,
    opcode_count: 0,
    start_validation_weight: 51,
    validation_weight: 51,
}
Time elapsed: 0ms